Add the following to your Page_Controller class:
public function getViewer($action) {
$viewer = parent::getViewer($action);
$this->extend('updateViewer', $action, $viewer);
return $viewer;
}
Add configuration to bind the extension into place
SilverStripe\CMS\Model\SiteTree:
extensions:
- Symbiote\UserTemplates\UserTemplatesExtension
PageController:
extensions:
- Symbiote\UserTemplates\UserTemplatesControllerExtension